Popped volcanic ash cover for liquids



United States Patent G ice over thesurface .of the liquids, thus considerably feduc: .ing their vapor pressure. 2 926 988 '.,Therefor.e, according to this invention, there ISJPI'O- vided a method for covering aliquid surface wh ch com- PQPPED VOLCANIC ASH COVER'FQR LIQUIDS 5 prises floating thereon popped volcanic ash.

Ordinarily, popped volcanic ash, .asprepai'eg, .wi'llbnot y float 100 percent upon aliqujid such as a yro'car on. Petroleum Company, a corporation of Delaware There will be particles especially h smallerlparficlgs No Drawing. ApplicationjiFebrnary 2 1 1955 which for purposes of thisinvention may he vtermed in- Serial No.'489,733 10 ufli iemly popped, which will not float on ,the liqgid. In one form of the invention,,the popped vo canic as is Chums (CL 605) floated upon the liquid an Particlhs hich W 1. fl are allowed to fall to the bottom of the container and can be recovered, although this method of operation is This invention relates to popped-volcanic ash as .a 15 not preferred. Ina preferred method of operatio cover for liquids. In one of its aspects theinventio'n cordingto the .invention, the popped volcanic ash, .is relates to the use of popped volcanicashas axcoverffo'r floated upon a portion of the liquid tom-protected or liquids which are ordinarily lost by evaporation. In upon a liquid which is similar to the liquidto be pr another of its aspects it relates to the use of popped tected inthe sense that the segregation of thenbnrfloat hg volcanic ash as a protective cover for liquids tofprevent particles, that is particles which will notfloat' upon the these against contamination by air or materials which liquid to be protected, is thus accomplished. may be floating in the air. In anotheraspect of thefin- It is noteworthy that various methods ,of segregating vention it relates to the segregation from popped 3101- the desirable from-the undesirable particles will'be apcanic ash of a floating portion by floating the volcanic parent to one skilled in the art in possession of this disash upon a portion of the liquid which is .to be proclosure. Therefore, this disclosure does not exhaustively tected and allowing a non-floating portion to be sepmention all the various methods which can be applied arated therefrom by sinking through the liquid. In within the scope of the invention to segregatethe desiranother aspect of the invention the popped volcanic ash able fromthe undesirable particles ofthe popped volis merely directly floated upon the liquid to be protected canic ash. v in case the non-floating portion of thepopped volcanic Another methodof separating the desirable from the ash is not detrimental to the liquid. In a still further undesirable particles of volcanic ash .is mechanical in aspect of the invention popped volcanic ash .is floated character in the sense that a screening oftheipoppcd volupon a salt water pit to prevent air from being dissolved canic ash, as produced, is effected to :retainon the-screen into the salt water, thus reducing substantially the coronly those particles which are of size suflicient, and,

Patented Mar. 1, 1960 James R. Hurley, Bartlesville, 0kla., assignor-tolhillips rosion of equipment used to pump the salt water to a therefore, of sufliciently low density, to float upon the place of utilization. In a still further aspect of the inliq i t is desired to Protect vention it relates to elutriation of popped volcanic ash by screening or other methods to .select therefrom a particularly suitable fraction of material .for one or more r reducing vaporlossor for protect nglh iq i irom or" the uses according to the invention. In' a qfurther 40 contamination y a need he 0111y k ml hio comaspect, still, the invention relates to the improvement P y cover the Surface of the liquid- However, it is of the ability of a popped volcanic ash to undergo segpossible to use thicknesses of up toan inch or greater. regation to separate from it particles which do not float Since the invention is pfeelhihently Suited fOT the P by subjecting said ash to at least one treatment which tection of Crude Oil in g it will now he exemplified comprises pla i it under a r d d pressure, in connection with such an application. However, it is A method of converting volcanic ash to cellular par- Possible Within the Scope of the invention to use P p ticles or so-called popped volcanic ash is described in P t n 2,637,702 f M 5, 1953, problem of protecting'the' liquid either against loss by Vapor loss from volatile liquids in open tanks or other evaporation y contamination y the or materials tanks and containers that are not vapor tight has been floating in the air, against hfiatrfil'e hazard, 7 a problem for a great many years. Various attacks Example I upon the problem have yielded varying degrees of success. However, in most instances the storage of a liquid while preventing substantial losses therefrom by evaporation has been an expensive matter. The same observation is made with respect to the storage of liquids in containers which in elfect are open pits of vast surface area and which, therefore, require expensive covers covered with a floating layer of popped volcanic ash' approximately one inch thick, the other was left uncovered. Periodic checks were made for evaporation loss. The results of the test appear below.

to prevent the stored liquids from becoming contamvolume liquid 10st inated by the oxygen of the air or other materials in pe cent the air which are undesirable in the said liquids. Thus, Time, hours floating roofs have been used on tanks to reduce the Wiflmui with P pp d popped vapor loss. Also, extensive vapor recovery systems have ash' ash been installed. More recently it has been suggested that small plastic balloons which are so small that they r 0.9 0.3 are referred to as microballoons be employed to cut 2:; if; down on loss by evaporation from storage tanks. 2-;

I have now found that popped volcanic ash can be 814 311 floated upon liquids, especially hydrocarbon liquids, which g: g are stored in vessels which are not vapor tight. The 14.4 9.7

small particles of popped volcanic ash can be distributed The thickness -of the layer of popped volcanic. ash which can be floated upon the surface of the stored liquidvolcanic ash upon any liquid Where: there is involved a Two, 200 ml. samples of Wafra No. 4 crude were. placed in an oven at F. .One of the samples was 7 At the end of the test described above, only about 25 percent of the popped ash remained as a floating layer while the rest had sunk. Thus, according tothis invention, and as an important feature thereof, only a small fraction of the popped ash consists of imperforate cells which will float indefinitely. This was verified by tests in which 10 grams of ash were suspended in each of water, toluene (32 API), and iso-octane (73 API). After 552 hr. (equilibrium essentially reached by intermittent agitation), there remained 26 ml. of stable foam on water, 9 ml. on toluene, and 6 ml. on iso-octane whereas initially the foam volume was about 75 ml.

Tests also showed that when a slurry of the popped ash was subjected several times to a vacuum and then to air at atmospheric pressure, equilibrium was attained in a few minutes.

It will be noted from the foregoing example and tests that the invention is suited to the covering of various types of liquids, organic and inorganic in character. Further, it will be understood that another important feature of the invention is the treatment of the volcanic ash to successive pressure changes as in the last-described tests. Thus, it is within the scope of the invention to subject the popped volcanic ash to a vacuum and then to atmospheric pressure in order to improve its ability to segregate when placed upon the liquid.

Example II Ten grams of the ash were added to 200 ml. of water in a graduate, shaken, and allowed to stand. Within 60 seconds, nearly all of the popped ash had floated to the top and at the end of three minutes the mat had formed so firmly that the cylinder could be inverted and shaken without spilling any water.

Reasonable variation and modification are possible within the scope of the foregoing disclosure and the appended claims to the invention, the essence of which is that popped volcanic ash has been found useful for the covering of liquids, as described, and that certain preferred methods for treatment of the popped volcanic ash in to render it even more useful by eliminating from it certain non-floating portions have been set forth, also as described.

I claim:

1. A method for protecting a liquid against loss of volatile components thereof to the atmosphere or its contamination by said atmosphere which comprises subjecting popped volcanic ash to a reduced pressure, then floating said popped volcanic ash upon a separate body of said liquid, allowing non-floating portions of the volcanic ash to separate from the remainder of the ash floating upon the surface of the said separate body of liquid recovering said remainder of ash from said separate body of liquid and then floating the said remainder of volcanic ash upon the remainder of said liquid in a quantity sufficient to substantially completely cover said liquid.

2. A method for storing an organic liquid which tends to lose its volatile components during storage which comprises subjecting popped volcanic ash to a reduced pressure, floating the popped volcanic ash upon a separate body of said liquid to allow the non-floating portion of said popped volcanic ash to separate from the floating portion of said popped volcanic ash and then floating said floating portio'n of said popped volcanic ash upon said organic liquid in a manner to substantially completely cover the same with a layer of floating popped volcanic ash, the subjecting to said reduced pressure improving the covering characteristics of the thus-treated popped volcanic ash.

References Cited in the file of this patent UNITED STATES PATENTS 1,415,351 Howard May 9, 1922 1,814,053 Mueller July 14, 1931 2,637,702 Burwell May 5, 1953 2,797,138 Veatch June 25, 1957 2,797,139 Veatch June 25, 1957 2,797,140 Veatch June 25, 1957 2,797,141 Veatch June 25, 1957 FOREIGN PATENTS 448,801 Germany Sept. 26, 1928 13,780 Australia Dec. 18, 1928 520,191 Belgium June 15, 1953 

1. A METHOD FOR PROTECTING A LIQUID AGAINST LOSS OF VOLATILE COMPONENTS THEREOF TO THE ATMOSPHERE OR ITS CONTAMINATION BY SAID ATMOSPHERE WHICH COMPRISES SUBJECTING POPPED VOLCANIC ASH TO A REDUCED PRESSURE, THEN FLOATING SAID POPPED VOLCANIC ASH UPON A SEPARATE BODY OF SAID LIQUID, ALLOWING NON-FLOATING PORTIONS OF THE VOLCANIC ASH TO SEPARATE FROM THE REMAINDER OF THE ASH FLOATING UPON THE SURFACE OF THE SAID SEPARATE BODY OF LIQUID RECOVER ING SAID REMAINDER OF ASH FROM SAID SEPARATE BODY OF LIQUID AND THEN FLOATING THE SAID REMAINDER OF VOLCANIC ASH UPON THE REMAINDER OF SAID LIQUID IN A QUANTITY SUFFICIENT TO SUBSTANTIALLY COMPLETELY COVER SAID LIQUID. 